This invention relates to a fluid valve assembly and particularly to a ballcock assembly which regulates the flow of water into a toilet reservoir tank.
Ballcock assemblies regulate the flow of water into the reservoir rank of conventional toilets to fill the tank to a desired level. When the toilet is flushed, water drains from the reservoir tank which must thereafter be refilled. Ballcock assemblies control tank refilling and have a float which senses the water level in the tank and stops the flow once a desired level is reached.
Designers of ballcock assemblies have made numerous attempts at making their operation quieter during tank refilling when water under high line pressure is being discharged into the reservoir tank. Typically, a so-called "hush" tube is provided which extends from the ballcock valve downward to the bottom of the reservoir tank. Once water begins to enter the tank during refilling, the outlet of the hush tube is submersed below water level which reduces annoying water rushing sounds. Although hush tubes operate satisfactorily, their use complicates the ballcock assembly structure by requiring additional components.
For sanitary considerations, ballcock assemblies must be provided with a means for preventing the reverse flow of water from the toilet water reservoir into the water supply line. Typically, a vacuum break is provided within the ballcock valve to prevent water from flowing from the hush tube into the water supply line when a subatmospheric pressure exists in the supply line. Although such vacuum break systems operate satisfactorily, it is desirable to provide additional safeguards to prevent water backflow.